path: root/net/ipv4/tcp_output.c
diff options
authorEric Dumazet <edumazet@google.com>2019-12-16 18:51:03 -0800
committerDavid S. Miller <davem@davemloft.net>2019-12-17 22:09:52 -0800
commit7c68fa2bddda6d942bd387c9ba5b4300737fd991 (patch)
tree3e77528920733f3ed1238495a95c87f9f5d59ac9 /net/ipv4/tcp_output.c
parentnet: qlogic: Fix error paths in ql_alloc_large_buffers() (diff)
net: annotate lockless accesses to sk->sk_pacing_shift
sk->sk_pacing_shift can be read and written without lock synchronization. This patch adds annotations to document this fact and avoid future syzbot complains. This might also avoid unexpected false sharing in sk_pacing_shift_update(), as the compiler could remove the conditional check and always write over sk->sk_pacing_shift : if (sk->sk_pacing_shift != val) sk->sk_pacing_shift = val; Signed-off-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to '')
1 files changed, 2 insertions, 2 deletions
diff --git a/net/ipv4/tcp_output.c b/net/ipv4/tcp_output.c
index 36902d08473e..1f7735ca8f22 100644
--- a/net/ipv4/tcp_output.c
+++ b/net/ipv4/tcp_output.c
@@ -1725,7 +1725,7 @@ static u32 tcp_tso_autosize(const struct sock *sk, unsigned int mss_now,
u32 bytes, segs;
bytes = min_t(unsigned long,
- sk->sk_pacing_rate >> sk->sk_pacing_shift,
+ sk->sk_pacing_rate >> READ_ONCE(sk->sk_pacing_shift),
sk->sk_gso_max_size - 1 - MAX_TCP_HEADER);
/* Goal is to send at least one packet per ms,
@@ -2260,7 +2260,7 @@ static bool tcp_small_queue_check(struct sock *sk, const struct sk_buff *skb,
limit = max_t(unsigned long,
2 * skb->truesize,
- sk->sk_pacing_rate >> sk->sk_pacing_shift);
+ sk->sk_pacing_rate >> READ_ONCE(sk->sk_pacing_shift));
if (sk->sk_pacing_status == SK_PACING_NONE)
limit = min_t(unsigned long, limit,